Forming process and forming system for aluminum-magnesium alloy special-shaped conical pipe

Abstract

The application discloses an aluminum-magnesium alloy special-shaped conical pipe forming process and a forming system, relates to the technical field of high-performance aluminum-magnesium alloy non-ferrous metal material processing, and the forming process comprises the following steps: (1) prefabricated pipe blank pre-positioning; (2) push head into pipe positioning and plugging; (3) liquid supplementing and pressure boosting; (4) extrusion deformation: the upper die and the lower die are mutually closed, at this time, the prefabricated pipe blank is deformed in cooperation under the outward supporting force of the high-pressure liquid and the inward extrusion of the upper die and the lower die forming cavities, a curved surface which is matched with the size and shape of the forming cavities is formed, and the aluminum-magnesium alloy special-shaped conical pipe is obtained. The process can realize one-time forming of special-shaped conical pipe processing, can integrally reduce the number of processes, reduce the processing cost, the size precision error of the prepared product is small, and the good product rate is as high as 95%.

Description

Technical Field

[0001] This invention relates to the field of high-performance aluminum-magnesium alloy non-ferrous metal material processing technology, and in particular to an aluminum-magnesium alloy irregular tapered tube forming process and forming system. Background Technology

[0002] Non-ferrous metals refer to all metals other than iron, chromium, manganese, and their alloys, including aluminum alloys, magnesium alloys, and titanium alloys. Existing aluminum-magnesium alloys possess extremely high specific strength (the ratio of strength to weight), meaning they are both lightweight and strong. Lightweighting is a perpetual goal in aerospace, automotive, and high-speed rail industries, significantly saving fuel / electricity, increasing speed, and improving load capacity. Magnesium alloys are even lighter than aluminum alloys, making them the lightest metal structural materials used in engineering applications, often for components with stringent weight requirements. High-performance aluminum alloys, magnesium alloys, titanium alloys, and other non-ferrous metal materials are used to manufacture precision components that meet extremely stringent standards (lightweight, high strength, high temperature resistance, and high reliability), fulfilling the core performance, safety, and efficiency requirements of modern aerospace vehicles, automobiles, and high-speed trains.

[0003] Irregularly shaped tapered tubes refer to tubing with a non-circular cross-section (such as pea-shaped, elliptical, racetrack-shaped, etc.) and a tapered shape. The processing of irregularly shaped tapered tubes is not a single method, but rather involves different combinations of processes selected based on precision requirements, batch size, and cost budget. Currently, the mainstream processing routes are as follows:

[0004] Traditional machining, a form of subtractive manufacturing, begins by selecting thick-walled aluminum-magnesium alloy tubing or solid bars, placing them on a CNC lathe or milling machine, and removing most of the excess material through turning and milling to initially form the inner and outer contours of the tapered tube. Then, multi-axis CNC machine tools are used for precision milling and turning to gradually machine the final irregular tapered tube's internal and external shape and dimensions. This machining approach is suitable for single-piece, small-batch, high-precision, and prototype manufacturing scenarios. Its core drawbacks are low material utilization, low efficiency, high cost, and difficulty in machining complex thin-walled structures.

[0005] Spin forming, a type of plastic forming, uses round tubes or slabs. First, the blank is pre-formed into an approximate shape using a stamping or deep drawing device. Then, on a CNC spinning machine, the blank rotates with the mandrel, and the spinning wheel, controlled by a computer, moves along a predetermined trajectory, applying pressure to the blank and causing it to gradually adhere to the mandrel point by point and line by line, resulting in plastic deformation and ultimately forming an irregularly shaped tapered tube. This processing method is suitable for small to medium batches of thin-walled, rotating irregularly shaped tapered tubes (such as elliptical tapered tubes). Its main drawbacks are high mold costs, long development cycles, and certain limitations on part shapes. Additionally, if the aluminum-magnesium alloy lacks sufficient plasticity, it is prone to cracking and other defects during spinning.

[0006] The main challenges in machining aluminum-magnesium alloy tapered tubes stem from their structural complexity and material properties. The combination of a non-circular cross-section and a tapered shape makes it difficult to form them in a single operation using existing machining methods. Furthermore, the residual stress within the aluminum-magnesium alloy blank is released during machining, leading to warping, twisting, and cracking of the workpiece. This results in large dimensional accuracy errors, a high defect rate, and high processing costs. Therefore, improvements to these technical issues are necessary. Summary of the Invention

[0007] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a forming process for aluminum-magnesium alloy irregular tapered tubes.

[0008] The second objective of this invention is to provide an aluminum-magnesium alloy irregular tapered tube forming system.

[0009] One of the objectives of this invention is achieved by the following technical solution: a forming process for an aluminum-magnesium alloy shaped tapered tube, wherein the aluminum-magnesium alloy shaped tapered tube is a tube with tapered ends and a non-circular, hollow, flat cross-section in the middle. The forming process for the aluminum-magnesium alloy shaped tapered tube includes the following steps:

[0010] (1) Pre-positioning of precast tube blank: The precast tube blank is placed in the tube head limiting cavity of the lower floating clamping block. Then the upper mold moves down, driving the upper floating clamping block down synchronously and gradually approaching the lower floating clamping block. The tube head limiting cavities on the upper and lower floating clamping blocks radially clamp the two ends of the precast tube blank. At this time, the middle part of the tube body of the precast tube blank is suspended in the forming cavity of the upper and lower molds and does not contact the inner wall of the forming cavity.

[0011] (2) Push head insertion and sealing: Start the thrust cylinder, first insert the large diameter push head from the large diameter end of the precast tube blank and seal the tube opening, and limit the small diameter end of the other end of the precast tube blank to the equal diameter limiting cavity of the upper and lower floating clamping blocks to perform secondary positioning of the horizontal position of the precast tube blank; at this time, insert the small diameter push head from the small diameter end of the precast tube blank.

[0012] (3) Liquid replenishment and pressurization: The large-diameter pusher is equipped with an internal liquid filling channel. Liquid is replenished to the liquid filling channel within 2 seconds. At the same time, the small-diameter pusher is inserted from the small-diameter end of the precast tube blank and the pipe opening is expanded and sealed according to the preset size to form a sealed state. The liquid in the pipe is pressurized by the pressurizing cylinder.

[0013] (4) Extrusion deformation: The main pressure cylinder moves further down, causing the upper and lower molds to close together. At this time, the preformed tube blank is deformed by the outward support force of the high pressure liquid and the inward extrusion of the upper and lower mold forming cavities, forming a curved surface that matches the size and shape of the forming cavity, thus obtaining an aluminum-magnesium alloy shaped tapered tube.

[0014] Furthermore, in the aluminum-magnesium alloy shaped tapered tube forming process, in step (2) pusher insertion and sealing, the output pressure of the large-diameter pusher is 10-15MPa, and the output pressure of the small-diameter pusher is 8-10MPa.

[0015] Furthermore, in the aluminum-magnesium alloy shaped conical tube forming process, in step (3) of replenishing and pressurizing, the pressurization process refers to increasing the hydraulic pressure of the liquid inside the tube to 70-80 MPa.

[0016] Furthermore, in the aluminum-magnesium alloy shaped tapered tube forming process, during step (4) extrusion deformation, the output pressure of the main pressure cylinder is 10-15 MPa.

[0017] Furthermore, in the aluminum-magnesium alloy shaped tapered tube forming process, after the upper and lower dies are closed to each other in the extrusion deformation step (4), the preformed tube blank is subjected to pressure holding treatment for 3-4 seconds.

[0018] Furthermore, the aluminum-magnesium alloy shaped tapered tube forming process also includes step (5) depressurization. After the tube is extruded and deformed, the pressure of the booster cylinder is withdrawn, and the hydraulic pressure in the tube blank is reduced to zero MPa. The liquid in the tube blank flows back into the booster cylinder.

[0019] Furthermore, the aluminum-magnesium alloy shaped tapered tube forming process also includes step (6) push head return stroke and mold removal. After depressurization, the large-diameter push head and the small-diameter push head return stroke respectively, the main pressure cylinder moves upward, the upper mold and the upper floating clamping block move upward synchronously, and the aluminum-magnesium alloy shaped tapered tube is taken out.

[0020] One of the objectives of this invention is achieved by the following technical solution: an aluminum-magnesium alloy shaped tapered tube forming system, comprising an upper mold, a lower mold, an upper floating block, a lower floating block, a large-diameter pusher, and a small-diameter pusher; the upper mold is provided with an upper forming groove and an upper floating block groove, the upper floating block groove being used to install the upper floating block and being disposed on both sides of the upper forming groove; the lower mold is provided with a lower forming groove and a lower floating block groove, the lower floating block groove being used to install the lower floating block and being disposed on both sides of the lower forming groove;

[0021] The upper floating block includes a first upper floating block and a second upper floating block, which are respectively installed on both sides of the upper forming groove. They move downward or upward with the upper mold. The first upper floating block and the second upper floating block are provided with an upper tube head limiting cavity and an upper push head feeding cavity. The lower floating block includes a first lower floating block and a second lower floating block, which are respectively installed on both sides of the lower forming groove. The first lower floating block and the second lower floating block are provided with a lower tube head limiting cavity and a lower push head feeding cavity.

[0022] The large-diameter pusher and the small-diameter pusher are movably mounted on both sides of the upper floating block and the lower floating block;

[0023] After the upper and lower molds are closed, the upper and lower push head feed cavities merge to form a feed chamber for feeding large-diameter push heads and small-diameter push heads, the upper and lower tube head limiting cavities merge to form a tube head limiting chamber for clamping both ends of the workpiece, and the upper and lower forming grooves merge to form a workpiece forming cavity.

[0024] Furthermore, in the aluminum-magnesium alloy shaped tapered tube forming system, one side of the tube head limiting chamber is tapered and used to limit the large-diameter tube opening, while the other side of the tube head limiting chamber is tapered and used to limit the small-diameter tube opening; the large-diameter pusher is provided with a sealing ring, while the small-diameter pusher is not provided with a sealing ring.

[0025] Furthermore, in the aluminum-magnesium alloy shaped tapered tube forming system, the first upper floating block and the second upper floating block are respectively installed at the bottom of the upper mold by equal-height screws to adjust the first upper floating block and the second upper floating block to have the same height level; the first lower floating block and the second lower floating block are respectively fixedly installed at the bottom of the lower mold by equal-height screws to adjust the first lower floating block and the second lower floating block to have the same height level; each of the above floating blocks is provided with an elastic element, and both the upper mold and the lower mold are provided with an elastic element mounting cavity for installing the elastic element.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. This application designs an aluminum-magnesium alloy shaped tapered tube forming system, employing liquid-filled forming technology. It utilizes the combined effect of external extrusion pressure and the reverse support force of high-pressure liquid inside the tube to obtain the desired shaped structure. Simultaneously, considering the characteristics of aluminum-magnesium alloy materials, a positioning structure with upper and lower floating blocks is added during processing. This ensures that the tube blank maintains its position within the mold during compression deformation, with the upper and lower molds fully closing. The upper and lower floating blocks are further compressed until the forming cavity completely fits the tube blank. The tension force is gradually supplied, effectively releasing residual stress within the aluminum-magnesium alloy blank during processing and effectively preventing warping, twisting, and cracking of the workpiece.

[0028] As can be seen, this process achieves one-time forming of irregularly shaped tapered tubes, which eliminates the need for multiple molds and processes such as pre-forming process / mold and final forming process / mold, thereby reducing processing costs. The resulting products have small dimensional accuracy errors, no warping, twisting, or cracking, and a yield rate as high as 90%.

[0029] 2. In the process of this invention, the curved surface forming structure of the metal parts utilizes the principle of fluid forming, which enables the profile to deform according to the preset shape. Specifically, the convex and concave templates cooperate with each other to adjust the stroke, pressure, positioning and other parameters in the vertical and axial directions, so that the precast tube blank forms a curved surface with a high degree of adaptability to the shape and size of the product.

[0030] 3. This application uses different sealing methods to seal the pipe openings. Preferably, the small-diameter pipe opening is sealed by expanding the pipe, and the large-diameter pipe opening is sealed by a sealing ring. This can effectively reduce the situation where pipe opening cracks lead to a sharp drop in yield.

[0031] 4. This application improves the adaptability of the device for processing tapered pipe fittings with non-equal axial diameters by designing a slider seat, thereby increasing the processing range of this device. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the aluminum-magnesium alloy shaped tapered tube product obtained by the present invention.

[0033] Figure 2 This is a schematic diagram of the defective aluminum-magnesium alloy shaped tapered tube obtained by the present invention.

[0034] Figure 3 This is a schematic diagram of the aluminum-magnesium alloy irregular tapered tube forming device according to a preferred embodiment of the present invention;

[0035] Figure 4 This is a top view of the aluminum-magnesium alloy irregular tapered tube forming apparatus according to a preferred embodiment of the present invention;

[0036] Figure 5 for Figure 4 A three-dimensional schematic diagram of the cross-section of line AA in the middle;

[0037] Figure 6 for Figure 5 Enlarged view of point a in the middle;

[0038] Figure 7 for Figure 5 Enlarged view of point b in the middle;

[0039] Figure 8 for Figure 4 A three-dimensional schematic diagram of the cross-section of the middle BB line;

[0040] Figure 9 for Figure 4 A three-dimensional cross-sectional view of the CC line;

[0041] Figure 10 This is a structural diagram of the upper or lower mold and the pusher head in a preferred embodiment of the present invention;

[0042] In the diagram: 1. Upper mold; 11. Upper forming groove; 12. Upper floating block groove; 13. Positioning guide post;

[0043] 2. Lower mold; 21. Lower forming groove; 22. Lower floating block groove; 23. Venting channel;

[0044] 3. Floating block; 31. First floating block; 311. Upper pipe head limiting cavity; 312. Upper pusher feed cavity; 32. Second floating block; 321. Upper pipe head limiting cavity; 322. Upper pusher feed cavity; 33. Height equalizing screw; 34. Elastic element;

[0045] 4. Lower floating block; 41. First lower floating block; 411. Lower pipe head limiting cavity; 412. Lower push head feed cavity; 42. Second lower floating block; 421. Lower pipe head limiting cavity; 422. Lower push head feed cavity; 43. Equal height screw; 44. Elastic element;

[0046] 5. Large-diameter pusher head; 51. Sealing ring; 52. Internal filling channel;

[0047] 6. Small-diameter pusher;

[0048] 7. Slider base;

[0049] 8. Push-head flange front plate;

[0050] 9. Upload the template;

[0051] 10. Download the template.

[0052] G. Aluminum-magnesium alloy shaped tapered tube; G1. Large diameter pipe opening; G2. Small diameter pipe opening; G3. Expanded pipe structure; G4. The cross-section of the middle part of the pipe body is non-circular and hollow flat. Detailed Implementation

[0053] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0054] The aluminum-magnesium alloy shaped tapered tube G processed by the present invention has tapered ends, i.e., one end is a large-diameter pipe opening G1 and the other end is a small-diameter pipe opening G2, and has a certain expansion structure G3, while the cross-section of the middle part of the tube body is non-circular and hollow and flat G4. Figure 1 As shown. The processing requirements for this workpiece are that there are no cracks at both ends of the tube, and the hollow flat tube in the middle is free of wrinkles and depressions, with uniform tube walls and no axial twist of the entire tube.

[0055] The forming process of this aluminum-magnesium alloy irregular tapered tube includes the following steps:

[0056] (1) Pre-positioning of precast tube blank: The precast tube blank is placed in the tube head limiting cavity of the lower floating clamping block. Then the upper mold moves down, driving the upper floating clamping block down synchronously and gradually approaching the lower floating clamping block. The tube head limiting cavities on the upper and lower floating clamping blocks radially clamp the two ends of the precast tube blank. At this time, the middle part of the tube body of the precast tube blank is suspended in the forming cavity of the upper and lower molds and does not contact the inner wall of the forming cavity. The precast tube blank refers to a hollow tube with tapered ends and a circular cross-section in the middle part of the tube body.

[0057] (2) Push head insertion and sealing: Start the thrust cylinder, first insert the large diameter push head from the large diameter end of the precast tube blank and seal the tube opening, and limit the small diameter end of the other end of the precast tube blank to the equal diameter limiting cavity of the upper and lower floating clamping blocks to perform secondary positioning of the horizontal position of the precast tube blank; at this time, insert the small diameter push head from the small diameter end of the precast tube blank.

[0058] (3) Liquid replenishment and pressurization: The large-diameter pusher is equipped with an internal liquid filling channel. Liquid is replenished to the liquid filling channel within 2 seconds. At the same time, the small-diameter pusher is inserted from the small-diameter end of the precast tube blank and the pipe opening is expanded and sealed according to the preset size to form a sealed state. The liquid in the pipe is pressurized by the pressurizing cylinder.

[0059] (4) Extrusion deformation: The main pressure cylinder moves further down, causing the upper and lower molds to close together. At this time, the preformed tube blank is deformed by the outward support force of the high pressure liquid and the inward extrusion of the upper and lower mold forming cavities, forming a curved surface that matches the size and shape of the forming cavity, thus obtaining an aluminum-magnesium alloy shaped tapered tube.

[0060] This application designs an aluminum-magnesium alloy shaped tapered tube forming device, employing liquid-filled forming technology. It utilizes the combined effect of external extrusion pressure and the reverse support force of high-pressure liquid inside the tube to obtain the desired shaped structure. Simultaneously, considering the characteristics of aluminum-magnesium alloy materials, a positioning structure with upper and lower floating blocks is added during processing. This ensures that the tube blank maintains its position within the mold during compression deformation, with the upper and lower molds fully closing. The floating blocks are further compressed until the forming cavity completely fits the tube blank. The tension is gradually supplied, effectively releasing residual stress within the aluminum-magnesium alloy blank during processing and effectively preventing warping, twisting, and cracking of the workpiece.

[0061] As can be seen, this process achieves one-time forming of irregularly shaped tapered tubes, eliminating the need for multiple molds and processes such as pre-forming / molding and final forming / molding, thus reducing processing costs. The resulting products have small dimensional accuracy errors, are free from warping, twisting, and cracking, and have a yield rate as high as 90%. Specifically, the upper and lower floating blocks in this forming device serve both as the entry point for the pusher in the liquid-filled forming technology and as axial and radial positioning and limiting structures for the preformed tube blank. Under the outward support force of the high-pressure liquid and the inward extrusion of the upper and lower forming cavities, the preformed tube blank deforms in coordination, forming a curved surface that matches the size and shape of the forming cavity, thereby improving the yield rate.

[0062] As a further preferred option, in the aluminum-magnesium alloy shaped tapered tube forming process, in step (2) pusher insertion and sealing, the output pressure of the large-diameter pusher is 10-15MPa, and the output pressure of the small-diameter pusher is 8-10MPa.

[0063] As a further preferred option, in the aluminum-magnesium alloy shaped tapered tube forming process, in step (3) of replenishing and pressurizing, the pressurization process refers to increasing the hydraulic pressure of the liquid inside the tube to 70-80 MPa.

[0064] As a further preferred option, in the aluminum-magnesium alloy shaped tapered tube forming process, in step (4) extrusion deformation, the output pressure of the main pressure cylinder is 10-15MPa.

[0065] As a further preferred option, in the aluminum-magnesium alloy shaped tapered tube forming process, after the upper and lower dies are closed to each other in the extrusion deformation step (4), the preformed tube blank is subjected to pressure holding treatment for 3-4 seconds.

[0066] As a further preferred option, the aluminum-magnesium alloy shaped tapered tube forming process also includes step (5) depressurization. After the tube is extruded and deformed, the pressure of the booster cylinder is withdrawn, and the hydraulic pressure in the tube blank is reduced to zero MPa. The liquid in the tube blank flows back into the booster cylinder.

[0067] As a further preferred option, the aluminum-magnesium alloy shaped tapered tube forming process also includes step (6) push head return stroke and mold removal. After depressurization, the large-diameter push head and the small-diameter push head return stroke respectively, the main pressure cylinder moves upward, the upper mold and the upper floating clamping block move upward synchronously, and the aluminum-magnesium alloy shaped tapered tube is taken out.

[0068] This invention also provides an aluminum-magnesium alloy irregular tapered tube forming system, such as... Figure 3-10As shown, it specifically includes an upper mold 1, a lower mold 2, an upper floating block 3, a lower floating block 4, a large-diameter pusher 5, and a small-diameter pusher 6; the upper mold 1 is provided with an upper forming groove 11 and an upper floating block groove 12, the upper floating block groove 12 is used to install the upper floating block 3 and is arranged on both sides of the upper forming groove 11; the lower mold 2 is provided with a lower forming groove 21 and a lower floating block groove 22, the lower floating block groove 22 is used to install the lower floating block 4 and is arranged on both sides of the lower forming groove 21;

[0069] The upper floating block 3 includes a first upper floating block 31 and a second upper floating block 32, which are respectively installed on both sides of the upper forming groove 11. They move downward or upward with the upper mold 1. The first upper floating block 31 and the second upper floating block 32 are provided with an upper tube head limiting cavity 311 / 321 and an upper push head feeding cavity 312 / 322. The lower floating block 4 includes a first lower floating block 41 and a second lower floating block 42, which are respectively installed on both sides of the lower forming groove 21. The first lower floating block 41 and the second lower floating block 42 are provided with a lower tube head limiting cavity 411 / 421 and a lower push head feeding cavity 412 / 422.

[0070] The large-diameter pusher 5 and the small-diameter pusher 6 are movably mounted on both sides of the upper floating block 3 and the lower floating block 4;

[0071] After the upper mold 1 and the lower mold 2 are closed, the upper and lower push head feed cavities are combined to form a feed chamber for feeding the large-diameter push head 5 and the small-diameter push head 6. The upper and lower tube head limiting cavities are combined to form a tube head limiting cavity for clamping both ends of the workpiece. The upper and lower forming grooves 21 are combined to form a workpiece forming cavity.

[0072] This application presents a system for forming aluminum-magnesium alloy shaped tapered tubes. Utilizing liquid-filled forming technology and leveraging the material properties of aluminum-magnesium alloys, it achieves one-step forming of the shaped tapered tube by combining extrusion pressure and the supporting force of high-pressure liquid inside the tube. This eliminates the need for multiple molds and processes, such as pre-forming / molding and final forming / molding. This forming system reduces overall processing steps and costs, resulting in products with low dimensional accuracy and a yield rate as high as 90%.

[0073] Specifically, the upper and lower floating blocks 3 / 4 of the design in this molding system serve as both the entry point for the pusher in the liquid filling molding technology and the axial and radial positioning and limiting structure for the preformed tube blank. Under the outward support force of the high-pressure liquid and the inward extrusion of the upper and lower mold forming cavities, the preformed tube blank deforms in coordination to form a curved surface that matches the size and shape of the forming cavity, thus avoiding warping, twisting, and cracking of the workpiece and improving the yield rate.

[0074] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, the first upper floating block 31 and the second upper floating block 32 are respectively installed at the bottom of the upper mold 1 by equalizing screws 33 to adjust the first upper floating block 31 and the second upper floating block 32 to have the same height level; the first lower floating block 41 and the second lower floating block 42 are respectively fixedly installed at the bottom of the lower mold 2 by equalizing screws 43 to adjust the first lower floating block 41 and the second lower floating block 42 to have the same height level; each of the above floating blocks is provided with an elastic element 34 / 44, and both the upper mold 1 and the lower mold 2 are provided with elastic element mounting cavities for mounting the elastic elements. The elastic element is preferably a compression spring. The tube head limiting cavity design of the upper floating block 3 and lower floating block 4 in this application provides radial and axial limiting for the tube blank positioning. The compression spring design ensures that the tube blank maintains its positioning position in the mold during compression deformation. When the upper mold 1 and lower mold are fully closed, the compression spring is further compressed until the forming cavity is completely in contact with the tube blank. This tension force is supplied gradually, which effectively releases the internal residual stress of the aluminum-magnesium alloy blank during processing and effectively avoids warping, twisting and cracking of the workpiece.

[0075] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, one side of the tube head limiting chamber is tapered and used to limit the large-diameter tube opening, while the other side of the tube head limiting chamber is tapered and used to limit the small-diameter tube opening.

[0076] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, a positioning guide post 13 is provided between the upper mold 1 and the lower mold 2. In order to further improve the vertical positioning between the upper mold 1 and the lower mold 2, the positioning guide post 13 is preferably designed to ensure that the upper mold 1 and the lower mold 2 are radially stable under force during the mold closing process.

[0077] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, the large-diameter pusher 5 is provided with a sealing ring 51, while the small-diameter pusher 6 is not provided with a sealing ring.

[0078] The diameter ratio of the two ends of the tapered tube processed by this invention is greater than 3, which makes it difficult to ensure the consistency of the pressure on the two ends. Therefore, cracking of the ends is likely to occur during the processing. To address this, it is preferable to use an expansion method to seal the smaller diameter end and a sealing ring method to seal the larger diameter end. This can effectively reduce the situation where cracking of the ends leads to a sharp drop in the yield.

[0079] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, the large-diameter pusher 5 is provided with an internal filling channel 52, which is connected to an external high-pressure cylinder (not shown in the figure).

[0080] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, the large-diameter pusher 5 and the small-diameter pusher 6 are respectively mounted on the front plate 8 of the pusher flange via a slider seat 7.

[0081] This application designs a slider seat 7, on which the pusher head is slidably mounted, thereby improving the adaptability for processing tapered pipe fittings with non-equal axial diameters and increasing the processing range of this device.

[0082] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, the front disc 8 of the pusher flange is powered for axial movement by a thrust cylinder (not shown in the figure).

[0083] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, the workpiece forming cavity is provided with an exhaust channel 23, which is connected to the external environment of the mold.

[0084] As a further preferred embodiment, in the aluminum-magnesium alloy shaped tapered tube forming system, an upper template 9 and a lower template 10 are fixedly installed on the outer sides of both the upper mold 1 and the lower mold 2. The lower template 10 is installed on a machine tool, and the upper template 9 is driven to move downward or upward by the main pressure cylinder.

[0085] Example 1

[0086] A type of aluminum-magnesium alloy shaped tapered tube G is a pipe fitting with tapered ends, i.e., one end is a large-diameter pipe opening G1 and the other end is a small-diameter pipe opening G2, and it has a certain expansion structure G3. The cross-section of the middle section of the tube is non-circular and hollow and flat G4. Figure 1 As shown.

[0087] The processing requirements for this workpiece are that there are no cracks at both ends of the tube, and the hollow flat tube in the middle is free of wrinkles and depressions, with uniform tube walls and no axial twist of the entire tube.

[0088] The forming process for this aluminum-magnesium alloy irregular tapered tube utilizes an aluminum-magnesium alloy irregular tapered tube forming system and includes the following steps:

[0089] (1) Pre-positioning of precast tube blank: The precast tube blank is placed in the tube head limiting cavity of the lower floating clamping block. Then the upper mold moves down, driving the upper floating clamping block down synchronously and gradually approaching the lower floating clamping block. The tube head limiting cavities on the upper and lower floating clamping blocks radially clamp the two ends of the precast tube blank. At this time, the middle part of the tube body of the precast tube blank is suspended in the forming cavity of the upper and lower molds and does not contact the inner wall of the forming cavity.

[0090] (2) Positioning and sealing of the pusher in the pipe: Start the thrust cylinder, first insert the large-diameter pusher into the pipe from the large-diameter end of the precast pipe blank and seal the pipe opening, and limit the small-diameter end of the other end of the precast pipe blank to the equal diameter limiting cavity of the upper and lower floating clamping blocks, and perform secondary positioning of the horizontal position of the precast pipe blank; at this time, insert the small-diameter pusher into the pipe from the small-diameter end of the precast pipe blank; in step (2) positioning and sealing of the pusher in the pipe, the output pressure of the large-diameter pusher is 15MPa and the output pressure of the small-diameter pusher is 8MPa.

[0091] (3) Liquid replenishment and pressurization: The large-diameter pusher is equipped with an internal liquid filling channel. Liquid is replenished to the liquid filling channel within 2 seconds. At the same time, the small-diameter pusher is inserted from the small-diameter end of the precast tube blank and the tube opening is expanded and sealed according to the preset size to form a sealed state. The liquid in the tube is pressurized by the pressurizing cylinder. In step (3) liquid replenishment and pressurization, the pressurization process refers to raising the hydraulic pressure of the liquid in the tube to 70-80 MPa.

[0092] (4) Extrusion Deformation: The main pressure cylinder moves further down, causing the upper and lower dies to close together. At this time, the preformed tube blank deforms under the outward support force of the high-pressure liquid and the inward extrusion of the upper and lower die forming cavities, forming a curved surface that matches the size and shape of the forming cavity, thus obtaining an aluminum-magnesium alloy shaped tapered tube. In step (4) extrusion deformation, the output pressure of the main pressure cylinder is 10MPa. After the upper and lower dies close together, the preformed tube blank is subjected to pressure holding treatment for 3-4 seconds.

[0093] (5) Pressure relief: After the pipe is extruded and deformed, the pressure of the booster cylinder is withdrawn, and the hydraulic pressure in the pipe blank is reduced to zero MPa. The liquid in the pipe blank flows back into the booster cylinder.

[0094] (6) Push head return stroke and mold removal: After depressurization, the large diameter push head and the small diameter push head return stroke respectively, the main pressure cylinder moves upward, the upper mold and the upper floating clamping block move upward simultaneously, and the aluminum-magnesium alloy special-shaped tapered tube is taken out.

[0095] Among them, such as Figure 3-10 As shown, the aluminum-magnesium alloy shaped tapered tube forming system of Embodiment 1 includes an upper mold 1, a lower mold 2, an upper floating block 3, a lower floating block 4, a large-diameter pusher 5, and a small-diameter pusher 6; the upper mold 1 is provided with an upper forming groove 11 and an upper floating block groove 12, the upper floating block groove 12 is used to install the upper floating block 3 and is arranged on both sides of the upper forming groove 11; the lower mold 2 is provided with a lower forming groove 21 and a lower floating block groove 22, the lower floating block groove 22 is used to install the lower floating block 4 and is arranged on both sides of the lower forming groove 21;

[0096] The upper floating block 3 includes a first upper floating block 31 and a second upper floating block 32, which are respectively installed on both sides of the upper forming groove 11. They move downward or upward with the upper mold 1. The first upper floating block 31 and the second upper floating block 32 are provided with an upper tube head limiting cavity 311 / 321 and an upper push head feeding cavity 312 / 322. The lower floating block 4 includes a first lower floating block 41 and a second lower floating block 42, which are respectively installed on both sides of the lower forming groove 21. The first lower floating block 41 and the second lower floating block 42 are provided with a lower tube head limiting cavity 411 / 421 and a lower push head feeding cavity 412 / 422.

[0097] The large-diameter pusher 5 and the small-diameter pusher 6 are movably mounted on both sides of the upper floating block 3 and the lower floating block 4;

[0098] After the upper mold 1 and the lower mold 2 are closed, the upper and lower push head feed cavities are combined to form a feed chamber for feeding the large-diameter push head 5 and the small-diameter push head 6. The upper and lower tube head limiting cavities are combined to form a tube head limiting cavity for clamping both ends of the workpiece. The upper and lower forming grooves 21 are combined to form a workpiece forming cavity.

[0099] Specifically, the first upper floating block 31 and the second upper floating block 32 are respectively installed at the bottom of the upper mold 1 by equalizing screws 33 to adjust the first upper floating block 31 and the second upper floating block 32 to have the same height level; the first lower floating block 41 and the second lower floating block 42 are respectively fixedly installed at the bottom of the lower mold 2 by equalizing screws 43 to adjust the first lower floating block 41 and the second lower floating block 42 to have the same height level; each of the above floating blocks is provided with an elastic element 34 / 44, and both the upper mold 1 and the lower mold 2 are provided with an elastic element mounting cavity for installing the elastic element.

[0100] One side of the pipe head limiting chamber is tapered, used to limit the large-diameter pipe opening, while the other side is equal-diameter, used to limit the small-diameter pipe opening. A positioning guide post 13 is provided between the upper mold 1 and the lower mold 2. A sealing ring 51 is provided on the large-diameter pusher 5, while the small-diameter pusher 6 does not. An internal filling channel 52 is provided on the large-diameter pusher 5, which is connected to an external high-pressure cylinder (not shown). The large-diameter pusher 5 and the small-diameter pusher 6 are respectively mounted on the pusher flange front plate 8 via a slider seat 7. The pusher flange front plate 8 is powered for axial movement by a thrust cylinder (not shown). An exhaust channel 23 is provided inside the workpiece forming cavity, which communicates with the external environment of the mold. An upper template 9 and a lower template 10 are fixedly installed on the outer sides of both the upper mold 1 and the lower mold 2. The lower template 10 is mounted on a machine tool, and the upper template 9 is driven downwards or upwards by a main pressure cylinder.

[0101] Example 2

[0102] An aluminum-magnesium alloy shaped tapered tube is a pipe fitting with tapered ends, i.e., one end is a large-diameter pipe opening and the other end is a small-diameter pipe opening, and has a certain expansion structure, while the cross-section of the middle part of the pipe body is non-circular and hollow flat.

[0103] The processing requirements for this workpiece are that there are no cracks at both ends of the tube, and the hollow flat tube in the middle is free of wrinkles and depressions, with uniform tube walls and no axial twist of the entire tube.

[0104] The forming process for this aluminum-magnesium alloy irregular tapered tube utilizes an aluminum-magnesium alloy irregular tapered tube forming system and includes the following steps:

[0105] (1) Pre-positioning of precast tube blank: The precast tube blank is placed in the tube head limiting cavity of the lower floating clamping block. Then the upper mold moves down, driving the upper floating clamping block down synchronously and gradually approaching the lower floating clamping block. The tube head limiting cavities on the upper and lower floating clamping blocks radially clamp the two ends of the precast tube blank. At this time, the middle part of the tube body of the precast tube blank is suspended in the forming cavity of the upper and lower molds and does not contact the inner wall of the forming cavity.

[0106] (2) Positioning and sealing of the pusher in the pipe: Start the thrust cylinder, first insert the large-diameter pusher into the pipe from the large-diameter end of the precast tube blank and seal the pipe opening, and limit the small-diameter end of the other end of the precast tube blank to the equal diameter limiting cavity of the upper and lower floating clamping blocks, and perform secondary positioning of the horizontal position of the precast tube blank; at this time, insert the small-diameter pusher into the pipe from the small-diameter end of the precast tube blank; in step (2) positioning and sealing of the pusher in the pipe, the output pressure of the large-diameter pusher is 12MPa and the output pressure of the small-diameter pusher is 9MPa.

[0107] (3) Liquid replenishment and pressurization: The large-diameter pusher is equipped with an internal liquid filling channel. Liquid is replenished to the liquid filling channel within 2 seconds. At the same time, the small-diameter pusher is inserted from the small-diameter end of the precast tube blank and the tube opening is expanded and sealed according to the preset size to form a sealed state. The liquid in the tube is pressurized by the pressurizing cylinder. In step (3) liquid replenishment and pressurization, the pressurization process refers to raising the hydraulic pressure of the liquid in the tube to 70-80 MPa.

[0108] (4) Extrusion Deformation: The main pressure cylinder moves further down, causing the upper and lower dies to close together. At this time, the preformed tube blank deforms under the outward support force of the high-pressure liquid and the inward extrusion of the upper and lower die forming cavities, forming a curved surface that matches the size and shape of the forming cavity, thus obtaining an aluminum-magnesium alloy shaped tapered tube. In step (4) extrusion deformation, the output pressure of the main pressure cylinder is 12MPa. After the upper and lower dies close together, the preformed tube blank is subjected to pressure holding treatment for 3-4 seconds.

[0109] (5) Pressure relief: After the pipe is extruded and deformed, the pressure of the booster cylinder is withdrawn, and the hydraulic pressure in the pipe blank is reduced to zero MPa. The liquid in the pipe blank flows back into the booster cylinder.

[0110] (6) Push head return stroke and mold removal: After depressurization, the large diameter push head and the small diameter push head return stroke respectively, the main pressure cylinder moves upward, the upper mold and the upper floating clamping block move upward simultaneously, and the aluminum-magnesium alloy special-shaped tapered tube is taken out.

[0111] The aluminum-magnesium alloy shaped tapered tube forming system used in this embodiment is the same as that in Embodiment 1.

[0112] Example 3

[0113] An aluminum-magnesium alloy shaped tapered tube is a pipe fitting with tapered ends, i.e., one end is a large-diameter pipe opening and the other end is a small-diameter pipe opening, and has a certain expansion structure, while the cross-section of the middle part of the pipe body is non-circular and hollow flat.

[0114] The processing requirements for this workpiece are that there are no cracks at both ends of the tube, and the hollow flat tube in the middle is free of wrinkles and depressions, with uniform tube walls and no axial twist of the entire tube.

[0115] The forming process for this aluminum-magnesium alloy irregular tapered tube utilizes an aluminum-magnesium alloy irregular tapered tube forming system and includes the following steps:

[0116] (1) Pre-positioning of precast tube blank: The precast tube blank is placed in the tube head limiting cavity of the lower floating clamping block. Then the upper mold moves down, driving the upper floating clamping block down synchronously and gradually approaching the lower floating clamping block. The tube head limiting cavities on the upper and lower floating clamping blocks radially clamp the two ends of the precast tube blank. At this time, the middle part of the tube body of the precast tube blank is suspended in the forming cavity of the upper and lower molds and does not contact the inner wall of the forming cavity.

[0117] (2) Push head insertion and sealing: Start the thrust cylinder, first insert the large diameter push head from the large diameter end of the precast tube blank and seal the tube opening, and limit the small diameter end of the other end of the precast tube blank to the equal diameter limiting cavity of the upper and lower floating clamping blocks to perform secondary positioning of the horizontal position of the precast tube blank; at this time, insert the small diameter push head from the small diameter end of the precast tube blank; in step (2) push head insertion and sealing, the output pressure of the large diameter push head is 10MPa and the output pressure of the small diameter push head is 10MPa.

[0118] (3) Liquid replenishment and pressurization: The large-diameter pusher is equipped with an internal liquid filling channel. Liquid is replenished to the liquid filling channel within 2 seconds. At the same time, the small-diameter pusher is inserted from the small-diameter end of the precast tube blank and the tube opening is expanded and sealed according to the preset size to form a sealed state. The liquid in the tube is pressurized by the pressurizing cylinder. In step (3) liquid replenishment and pressurization, the pressurization process refers to raising the hydraulic pressure of the liquid in the tube to 70-80 MPa.

[0119] (4) Extrusion Deformation: The main pressure cylinder moves further down, causing the upper and lower dies to close together. At this time, the preformed tube blank deforms under the outward support force of the high-pressure liquid and the inward extrusion of the upper and lower die forming cavities, forming a curved surface that matches the size and shape of the forming cavity, thus obtaining an aluminum-magnesium alloy shaped tapered tube. In step (4) extrusion deformation, the output pressure of the main pressure cylinder is 15MPa. After the upper and lower dies close together, the preformed tube blank is subjected to pressure holding treatment for 3-4 seconds.

[0120] (5) Pressure relief: After the pipe is extruded and deformed, the pressure of the booster cylinder is withdrawn, and the hydraulic pressure in the pipe blank is reduced to zero MPa. The liquid in the pipe blank flows back into the booster cylinder.

[0121] (6) Push head return stroke and mold removal: After depressurization, the large diameter push head and the small diameter push head return stroke respectively, the main pressure cylinder moves upward, the upper mold and the upper floating clamping block move upward simultaneously, and the aluminum-magnesium alloy special-shaped tapered tube is taken out.

[0122] The aluminum-magnesium alloy shaped tapered tube forming system used in this embodiment is the same as that in Embodiment 1.

[0123] Comparative Example 1

[0124] Compared with Example 2, the difference of the aluminum-magnesium alloy shaped tapered tube in Comparative Example 1 is that in step (2) the positioning and sealing of the pusher in the tube, the large and small diameter pushers are pushed synchronously, and the output pressure of the large and small diameter pushers is too high, both being 35MPa. The other processing conditions are the same as those in Example 1.

[0125] Comparative Example 2

[0126] Compared with Example 2, the difference of the aluminum-magnesium alloy shaped tapered tube in Comparative Example 2 is that in step (2) the positioning and sealing of the pusher in the tube, the large and small diameter pushers are pushed synchronously, and the output pressure of the large and small diameter pushers is too small, both being 18MPa. The other processing conditions are the same as those in Example 1.

[0127] Comparative Example 3

[0128] Compared with Example 2, the difference of the aluminum-magnesium alloy shaped tapered tube in Comparative Example 3 is that in step (3) replenishment and pressurization, the hydraulic pressure of the pressurization process is increased to 85 MPa, and the other processing conditions are the same as those in Example 1.

[0129] Comparative Example 4

[0130] Compared with Example 2, the difference of the aluminum-magnesium alloy shaped tapered tube in Comparative Example 4 is that in step (3) replenishment and pressurization, the hydraulic pressure of the pressurization process is increased to 65 MPa, and the other processing conditions are the same as those in Example 1.

[0131] Comparative Example 5

[0132] Compared with Example 2, the difference of Comparative Example 5 aluminum-magnesium alloy shaped tapered tube is that in the aluminum-magnesium alloy shaped tapered tube forming system, the upper and lower floating blocks lack compression springs, that is, in step (4) extrusion deformation: the main pressure cylinder goes further down, lacking the tension force to be supplied gradually, and the other processing conditions are the same as in Example 1.

[0133] Comparative Example 6

[0134] Compared with Example 2, the difference of Comparative Example 6, which uses an aluminum-magnesium alloy shaped tapered tube, is that in the aluminum-magnesium alloy shaped tapered tube forming system, the large and small diameter pushers are sealed by expanding the tube, or the large and small diameter pushers are sealed by sealing rings. All other processing conditions are the same as in Example 1.

[0135] Comparative Example 7

[0136] Compared with Example 2, the difference of Comparative Example 7, an aluminum-magnesium alloy shaped tapered tube, is that it uses existing conventional machining instead of the processing method of the present invention. Specifically, thick-walled aluminum-magnesium alloy tubes or solid bars are first selected and placed on a CNC lathe or milling machine. Most of the excess material is removed by turning and milling to initially form the inner and outer contours of the tapered tube. Then, a multi-axis CNC machine tool is used for precision milling and turning to gradually process the required inner and outer shapes and dimensions of the tapered tube.

[0137] Comparative Example 8

[0138] Compared with Example 2, the difference of Comparative Example 8, an aluminum-magnesium alloy shaped tapered tube, is that the existing spinning forming method is used instead of the processing method of the present invention. Specifically, a circular tube blank is used. First, the blank is pre-formed into an approximate shape by a stamping or deep drawing device. Then, on a CNC spinning machine, the blank rotates with the mandrel. The spinning wheel moves along a predetermined trajectory under computer control, applying pressure to the blank so that it adheres to the mandrel point by point and line by line, causing plastic deformation to obtain the shaped tapered tube.

[0139] The properties of the aluminum-magnesium alloy shaped tapered tubes processed in each example are measured below, as shown in Tables 1-2.

[0140] 1. The requirements for workpiece shape inspection are that there are no cracks at both ends of the tube, and the hollow flat tube body in the middle is free of wrinkles and depressions, with uniform tube wall and no axial twist of the entire tube body.

[0141] 2. Calculation of yield rate: The yield rate refers to the percentage of workpieces that pass the appearance inspection as good products and those that fail as defective products.

[0142] Table 1 Performance test results of aluminum-magnesium alloy tapered tubes in various examples

[0143]

[0144] Table 2. Yield (%) of aluminum-magnesium alloy tapered tubes in various examples.

[0145]

[0146] The data in the table above shows that the aluminum-magnesium alloy shaped tapered tubes produced by the process of the present invention have high dimensional accuracy, no cracks at both ends of the tube, no wrinkles or depressions in the hollow flat tube body in the middle, uniform tube wall, no axial twist of the overall tube body, and a yield rate of over 90%. The production cost is low. In particular, Example 1 is one of the optimal embodiments of the present invention, with high overall dimensional accuracy and a yield rate of over 95%.

[0147] Compared with Example 1, the difference between the aluminum-magnesium alloy tapered tubes in Comparative Examples 1-2 lies in the processing step (2). During the positioning and sealing of the pusher in the tube, the large and small diameter pushers are pushed synchronously. If the output pressure of the large and small diameter pushers is too high or too low, it will affect the axial positioning effect and the sealing effect of the tube blank, and it is easy for cracks to occur at the end of the tube. Figure 2 As shown.

[0148] Compared with Example 1, the difference between the aluminum-magnesium alloy shaped tapered tubes in Comparative Examples 3-4 lies in the hydraulic pressure increase during the liquid replenishment and pressurization process (3). If the hydraulic pressure is too high or insufficient, it affects the shape of the hollow, flat tube in the middle of the product to a certain extent. If the hydraulic pressure is too high, a local depression appears in the middle, resulting in insufficient flatness (e.g., ...). Figure 2 As shown in the figure, the hydraulic pressure is too low, the pipe wall thickness is large in the middle of the pipe body, and the pipe wall thickness is small at both ends.

[0149] Compared with Example 1, the difference of Comparative Example 5 aluminum-magnesium alloy shaped tapered tube is that in the aluminum-magnesium alloy shaped tapered tube forming system, the upper and lower floating blocks lack compression springs, which leads to a lack of tension force gradually supplied when the main pressure cylinder goes down further in step (4) extrusion deformation. As a result, the residual stress inside the aluminum-magnesium alloy blank cannot be effectively released during the processing, and the workpiece exhibits warping, twisting, and cracking.

[0150] Compared with Example 1, the difference of the aluminum-magnesium alloy shaped tapered tube in Comparative Example 6 is that in the aluminum-magnesium alloy shaped tapered tube forming system, when the large and small diameter pushers are sealed by expanding the tube, the hydraulic pressure of replenishing and pressurizing in step (3) cannot be effectively controlled, especially leakage at the large diameter tube end, and the product cannot continue to be processed. When the large and small diameter pushers are sealed by sealing rings, a secondary tube expansion process is required for the pipe fitting, which cannot be integrally formed, increasing the production cost.

[0151] Compared with Example 1, the aluminum-magnesium alloy shaped tapered tube of Comparative Example 7 is different in that it is made by conventional machining, specifically by CNC lathe or milling machine for material reduction. The middle part of the shaped tapered tube is irregularly flat, which is difficult to process. This process cannot produce the workpiece of the present invention, resulting in high material consumption and high production cost, which is twice the processing cost of the present invention.

[0152] Compared with Example 1, the difference of Comparative 8 aluminum-magnesium alloy shaped tapered tube is that it is made by existing spinning forming. The middle part of the shaped tapered tube is irregularly flat, which makes it difficult to process. The uniformity of the workpiece wall thickness is difficult to control. The end needs to be expanded twice. It cannot be formed in one piece, resulting in high production cost, which is 1.5 times that of the present invention.

[0153] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A forming process for aluminum-magnesium alloy irregular tapered tubes, characterized in that, The aluminum-magnesium alloy shaped tapered tube is a tube with tapered ends and a non-circular, hollow, flat cross-section in the middle. The forming process of the aluminum-magnesium alloy shaped tapered tube includes the following steps: (1) Pre-positioning of precast tube blank: The precast tube blank is placed in the tube head limiting cavity of the lower floating clamping block. Then the upper mold moves down, driving the upper floating clamping block down synchronously and gradually approaching the lower floating clamping block. The tube head limiting cavities on the upper and lower floating clamping blocks radially clamp the two ends of the precast tube blank. At this time, the middle part of the tube body of the precast tube blank is suspended in the forming cavity of the upper and lower molds and does not contact the inner wall of the forming cavity. (2) Push head insertion and sealing: Start the thrust cylinder, first insert the large diameter push head from the large diameter end of the precast tube blank and seal the tube opening, and limit the small diameter end of the other end of the precast tube blank to the equal diameter limiting cavity of the upper and lower floating clamping blocks to perform secondary positioning of the horizontal position of the precast tube blank; at this time, insert the small diameter push head from the small diameter end of the precast tube blank. (3) Liquid replenishment and pressurization: The large-diameter pusher is equipped with an internal liquid filling channel. Liquid is replenished to the liquid filling channel within 2 seconds. At the same time, the small-diameter pusher is inserted from the small-diameter end of the precast tube blank and the pipe opening is expanded and sealed according to the preset size to form a sealed state. The liquid in the pipe is pressurized by the pressurizing cylinder. (4) Extrusion deformation: The main pressure cylinder moves further down, causing the upper and lower molds to close together. At this time, the preformed tube blank is deformed by the outward support force of the high pressure liquid and the inward extrusion of the upper and lower mold forming cavities, forming a curved surface that matches the size and shape of the forming cavity, thus obtaining an aluminum-magnesium alloy shaped tapered tube.

2. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 1, characterized in that, In step (2) of positioning and sealing the pusher in the pipe, the output pressure of the large-diameter pusher is 10-15MPa, and the output pressure of the small-diameter pusher is 8-10MPa.

3. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 1, characterized in that, In step (3) replenishment and pressurization, the pressurization process refers to increasing the hydraulic pressure of the liquid in the pipe to 70-80 MPa.

4. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 1, characterized in that, In step (4) extrusion deformation, the output pressure of the main pressure cylinder is 10-15 MPa.

5. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 1, characterized in that, In step (4) extrusion deformation, after the upper and lower dies close to each other, the precast tube blank is subjected to pressure holding treatment for 3-4 seconds.

6. The aluminum-magnesium alloy shaped tapered tube forming process according to any one of claims 1-5, characterized in that, It also includes step (5) depressurization. After the pipe is extruded and deformed, the pressure of the booster cylinder is withdrawn, and the hydraulic pressure in the pipe blank is reduced to zero MPa. The liquid in the pipe blank flows back into the booster cylinder.

7. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 6, characterized in that, It also includes step (6) push head return stroke and mold removal. After depressurization, the large diameter push head and small diameter push head return stroke respectively, the main pressure cylinder moves upward, the upper mold and the upper floating clamping block move upward synchronously, and the aluminum-magnesium alloy special-shaped tapered tube is taken out.

8. The aluminum-magnesium alloy shaped tapered tube forming process according to any one of claims 1-5, characterized in that, The process employs an aluminum-magnesium alloy shaped tapered tube forming system, which includes an upper mold, a lower mold, an upper floating block, a lower floating block, a large-diameter pusher, and a small-diameter pusher. The upper mold is provided with an upper forming groove and an upper floating block groove, the upper floating block groove being used to install the upper floating block and positioned on both sides of the upper forming groove. The lower mold is provided with a lower forming groove and a lower floating block groove, the lower floating block groove being used to install the lower floating block and positioned on both sides of the lower forming groove. The upper floating block includes a first upper floating block and a second upper floating block, which are respectively installed on both sides of the upper forming groove. They move downwards or upwards with the upper mold. The first upper floating block and the second upper floating block are provided with an upper tube head limiting cavity and an upper push head feeding cavity. The lower floating block includes a first lower floating block and a second lower floating block, which are respectively installed on both sides of the lower forming groove. The first lower floating block and the second lower floating block are provided with a lower tube head limiting cavity and a lower push head feeding cavity. The large-diameter pusher and the small-diameter pusher are movably mounted on both sides of the upper floating block and the lower floating block; After the upper and lower molds are closed, the upper and lower push head feed cavities merge to form a feed chamber for feeding large-diameter push heads and small-diameter push heads, the upper and lower tube head limiting cavities merge to form a tube head limiting chamber for clamping both ends of the workpiece, and the upper and lower forming grooves merge to form a workpiece forming cavity.

9. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 8, characterized in that, One side of the pipe head limiting chamber is tapered and used to limit the large-diameter pipe opening, while the other side is equal in diameter and used to limit the small-diameter pipe opening. The large-diameter pusher is equipped with a sealing ring, while the small-diameter pusher is not equipped with a sealing ring.

10. The aluminum-magnesium alloy shaped tapered tube forming process as described in claim 8, characterized in that, The first and second upper floating blocks are respectively installed at the bottom of the upper mold using equal-height screws to adjust the first and second upper floating blocks to have the same height level; the first and second lower floating blocks are respectively fixedly installed at the bottom of the lower mold using equal-height screws to adjust the first and second lower floating blocks to have the same height level; each of the above floating blocks is provided with an elastic element, and both the upper and lower molds are provided with elastic element mounting cavities for mounting the elastic elements.

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